Clean fish and cut into pieces.
Grate coconut and grind ¼ parts into fine paste and keep aside.
Take 1 cup of first coconut milk and 3 cups of second coconut milk from the rest of grated coconut.
Place a clay pot on flame and pour in the coconut oil.
Roast fenugreek until its color turns dark brown.
Add sliced onions and sauté until it become translucent.
Add coriander powder after reducing flame to minimum or removing the pot from the fire. Roast it for 1 minute in lowest flame.
Add chilly powder and roast until the color changes to bright red.
Immediately add sliced tomatoes and curry leaves & continue sauté.
Add coconut paste and sauté until oil separates.
Add second coconut milk after mixing 1 tsp nice rice powder in it.
Add mangoes into the gravy and let the gravy bubble, in good flame.
Add fish pieces and salt and cook the curry with closed lid in low fire.
When fish pieces are cooked well and gravy reduced ¾ parts, add thick coconut milk.
Stir. Do not allow the gravy to boil after adding thick coconut milk.
Remove from fire.
Place a small kadai on fire pour in 2 tbsp coconut oil and fry sliced shallots until golden brown. Add curry leaves, fry and pour in the curry.
:- Serve with hot rice.